using System.Text;
using System.Text.Json;
using System.Web;
using MetaforceInstaller.Cloud.Implementations.MailRu.DTO;
using MetaforceInstaller.Cloud.Models;

namespace MetaforceInstaller.Cloud.Implementations.MailRu;

public class MailRuCloudService : ICloudService
{
    private const string BaseUrl = "https://cloud.mail.ru";

    private static readonly JsonSerializerOptions JsonOptions = new()
    {
        PropertyNameCaseInsensitive = true
    };

    private readonly HttpClient _httpClient;

    public MailRuCloudService(HttpClient httpClient)
    {
        _httpClient = httpClient;
    }

    public async Task<List<CloudObject>> GetObjects(string webLink)
    {
        var dto = await GetFromPublicApi<CloudObjectsResponse>(
            path: "/api/v4/public/list",
            query: new Dictionary<string, string?>
            {
                ["weblink"] = webLink,
                ["sort"] = "name",
                ["order"] = "asc",
                ["offset"] = "0",
                ["limit"] = "500",
                ["version"] = "4"
            }).ConfigureAwait(false);

        if (dto?.List is null || dto.List.Count == 0)
            return [];

        var result = new List<CloudObject>(dto.List.Count);
        foreach (var entry in dto.List)
            result.Add(Map(entry));

        return result;
    }

    public async Task<string?> GetDownloadLink(IEnumerable<string> webLinks, string outputFileName = "archive")
    {
        var result = await PostToPublicApi<ZipWebLinkResponse>(
            path: "/api/v3/zip/weblink",
            query: new Dictionary<string, string?>(),
            new ZipWebLinkRequest
            {
                XEmail = "anonym",
                WeblinkList = webLinks.ToList(),
                Name = outputFileName
            }
        );
        
        return result?.Key;
    }

    private async Task<TResponse?> GetFromPublicApi<TResponse>(string path, IReadOnlyDictionary<string, string?> query)
    {
        var uri = BuildUri(path, query);

        using var response = await _httpClient.GetAsync(uri).ConfigureAwait(false);
        response.EnsureSuccessStatusCode();

        var json = await response.Content.ReadAsStringAsync().ConfigureAwait(false);
        return JsonSerializer.Deserialize<TResponse>(json, JsonOptions);
    }

    private async Task<TResponse?> PostToPublicApi<TResponse>(string path, IReadOnlyDictionary<string, string?> query,
        object body)
    {
        var uri = BuildUri(path, query);

        var jsonBody = JsonSerializer.Serialize(body, JsonOptions);
        using var content = new StringContent(jsonBody, Encoding.UTF8, "application/json");

        using var response = await _httpClient.PostAsync(uri, content).ConfigureAwait(false);
        response.EnsureSuccessStatusCode();

        var json = await response.Content.ReadAsStringAsync().ConfigureAwait(false);
        return JsonSerializer.Deserialize<TResponse>(json, JsonOptions);
    }

    private static Uri BuildUri(string path, IReadOnlyDictionary<string, string?> query)
    {
        var builder = new UriBuilder(BaseUrl)
        {
            Port = -1,
            Path = path
        };

        var qs = HttpUtility.ParseQueryString(builder.Query);
        foreach (var (key, value) in query)
            qs[key] = value;

        builder.Query = qs.ToString();
        return builder.Uri;
    }

    private static CloudObject Map(CloudObjectBase entry)
    {
        return new CloudObject
        {
            Name = entry.Name,
            WebLink = entry.WebLink,
            Type = entry.Type == "folder" ? CloudObjectType.Folder : CloudObjectType.File
        };
    }
}